The body's first line of defense against pathogens is the innate immune system. Which of the following is NOT a component of the innate immune system?

Correct Answer: D

Rationale: The production of antibodies specific to a particular pathogen is a function of the adaptive immune system, not the innate immune system. The innate immune system provides immediate, non-specific defense mechanisms against pathogens, including physical barriers, phagocytes, and inflammatory responses. Choices A, B, and C are all correct components of the innate immune system. Physical barriers like skin and mucous membranes act as the first line of defense, preventing pathogens from entering the body. Phagocytes are specialized cells that engulf and destroy pathogens, while the inflammatory response helps isolate and contain infections to prevent their spread.

Correct Answer: C

Rationale: A) Unprotected sexual contact is a common route of transmission for sexually transmitted infections (STIs) as many STIs are spread through genital, anal, or oral sex without the use of barrier protection such as condoms. B) Sharing contaminated needles can also transmit STIs such as HIV and hepatitis B and C, especially among individuals who inject drugs. C) Deep kissing, while it can transmit certain infections like herpes simplex virus (HSV-1) or cytomegalovirus (CMV), is not a common route of transmission for most STIs. Although some STIs can be transmitted through saliva, deep kissing is not a primary mode of transmission for most STIs. D) Mother to child transmission during childbirth can occur with certain STIs such as HIV, syphilis, and herpes, where the infection can be passed from the mother to the baby during delivery. Therefore, deep kissing (option C) is the correct answer as it is not a typical route of transmission for most STIs.

Correct Answer: A

Rationale: An asymptomatic carrier is a person who carries a pathogen, such as a virus or bacterium, without showing any symptoms of the infection. Despite lacking symptoms, asymptomatic carriers can still transmit the pathogen to others, potentially causing illness in those they contact. This term specifically pertains to infected individuals who do not manifest symptoms, distinguishing them from symptomatic carriers who do exhibit signs of the infection. Option A is the most fitting choice as it accurately characterizes a person carrying a pathogen without displaying symptoms. B) Opportunistic pathogen: This term describes pathogens that typically do not cause disease in healthy individuals but can be pathogenic in those with weakened immune systems. C) Nosocomial infection: This term refers to infections acquired in a hospital or healthcare facility. D) Vector-borne disease: This term relates to diseases transmitted to humans by vectors like mosquitoes or ticks.

Correct Answer: C

Rationale: Producers, such as plants, algae, and some bacteria, are the organisms in a food chain that capture energy from the sun through the process of photosynthesis. They convert sunlight into chemical energy, which is then passed on to other organisms in the food chain. Producers are at the base of the food chain and form the foundation for all other trophic levels to obtain energy. Decomposers (option A) break down organic matter, carnivores (option B) consume other animals, and omnivores (option D) consume both plants and animals, but they do not directly capture energy from the sun.

Correct Answer: B

Rationale: The correct answer is B: Base. A base is a substance that can donate hydroxide ions (OH-) in solution. Bases increase the concentration of hydroxide ions by either accepting protons (H+) or donating hydroxide ions. Salts are ionic compounds made of cations and anions, which do not directly donate hydroxide ions. Neutral compounds do not significantly affect the concentration of hydroxide ions. Dehydrating agents are substances that remove water molecules from other compounds, unrelated to donating hydroxide ions.